Yoenis Cespedes on Rusney Castillo: "If he’s not a five-tool player, he’s a least a four-tool player. He’s very comparable to [Dodgers outfielder Yasiel] Puig. Obviously a different height and size, but very similar qualities." (AP)

There are few ways in the modern game of baseball to drastically improve your team without sacrificing the future. Pay the price for a top free agent and you really pay the price later.

Signing a big-name FA has turned into a risky proposition because it often requires a contract of at least five years and nine figures. Can you name any $100-million free-agent deal so far that has shown signs of working out?

Each one of those players' teams would likely choose financial flexibility over having that player on the roster moving forward. Werth is still productive, Kemp is heating up and Hamilton is enjoying a rebound season, but for those prices?

Free agency is not what it used to be. The prices have skyrocketed while the talent level has dwindled. Teams no longer let their stars reach the open market. Players are routinely locked up to humongous deals either before or during their arbitration years. There are no more Mike Trouts or Troy Tulowitzkis or Ryan Brauns or Evan Longorias in free agency.

The only two ways teams can infuse difference-making talent into their systems while avoiding being crippled financially are through the draft or in international free agency.

Castillo, 27, is an athletic centerfield prospect who added 20 pounds of muscle to his frame between the last time scouts saw him in Cuba and his recent private workouts with teams. The weight enabled him to, according to reports, add loft and power to his swing. Fellow Cuban outfielder Yoenis Cespedes recently called Castillo a four- or five-tool player very similar to Yasiel Puig.

Castillo was already regarded as a speedy, defensive-minded centerfielder with a line-drive stroke. The added power has added suitors to the mix, and George A. King of the New York Post reported last week that Castillo "could command as much as $35 to $45 million."

Puig is one of the top 10 players in baseball. He signed a seven-year, $42 million deal with the Dodgers that runs through 2018.

Abreu is a lock for AL Rookie of the Year and may even win AL MVP if he remains hot in the second half. He's hit .307 with a .628 slugging percentage, 28 doubles, 31 homers and 86 RBIs in 98 games for the White Sox. His deal was for six years and $68 million, just over $11M per season.

Cespedes isn't as complete a player as the other two, but certainly matches them in raw power and athleticism. His pact was for four years at $36 million.

That's three top-flight offensive players earning between $6 million and $11 million per season. Put any of them on the free-agent market tomorrow and they'd command at least $18 million annually.

That right there is why the Phillies must take a chance on Castillo. If he's the next Puig or Cespedes, or even if he's a tick below those two, he'd still likely outperform a mid-level baseball contract. There's just such a huge difference between the money paid to international free agents and money paid to proven major-leaguers. Kyle Kendrick will earn more this season than Puig, for example.

Thinking inside the box has the Phillies where they are now. But over the last two years they've shown an increased willigness to spend on unknown quantities. They signed Miguel Alfredo Gonzalez out of Cuba last summer, and already this summer they've brought in young shorstops Arquimedez Gamboa and Daniel Brito from Venezuela for a combined $1.5 million, shortstop Jonathan Arauz of Panama for $600,000, catcher Lenin Rodriguez from Venezuela for $300,000 and Panamaian southpaw Jhon Nunez for $80,000.

If the Phils sign Castillo and the move hits, all of the sudden they have an outfielder in his prime to build around. It would make up for the failure that was/is Domonic Brown.

If the Phils sign Castillo and it doesn't work out, then they're out $35-50 million. That would be a lot of money to throw away -- and the Phillies have certainly thrown money away under Ruben Amaro Jr.'s tenure -- but the reward outweighs the risk. It may even outweigh the risk if the expected bidding war between the Phils, Red Sox, Yankees and Mariners, among others, raises the price by another $10-15 million.